Let’s say I have a cube moving along the X axis. I want a sphere to move along the Y axis, with it’s Y Location being driven by the cube’s X Location. I know how to do this instantly in 2.4x, but I simply cannot work out how to do it in 2.5!
I found 2.5’s ‘Drivers’ screen in the Graph editor, and found a command called ‘Add Driver’ on the search menu… but whatever I try I just can’t find out how to assign Cube’s X Loc to Sphere’s Y Loc (and insert a 1:1 mapping curve) like I could in 2.49.
OK, so trying with a single cube to start with: I managed to give the cube’s X Location a driver. Then, in the Driver window of the Graph editor, I assigned a Sine function modifier. But when I play the animation, the X location of the cube doesn’t oscillate at all? Why isn’t the driver affecting the cube’s location?
Yeah, I think you are right, it probably should be reported as a bug.
Try out this file. I added a driver to the X location and added sine wave modifier and applied to the x location and clicked update dependencies. But nothing. It does not move.
Many thanks for testing this. Yep, when I Ioad your file there is no movement on the cube, so I guess it is broken in Blender and not my stupidity causing it!
Even if it was basically working, I still can’t work out how to assign one object’s X Location to another object’s Y Location, like I could in 2.4x…
Disregarding the sine wave issue, I have now made the Cube’s X Loc drive the Sphere’s Y Loc. The cure is described below.
In the drivers pane, I am viewing the Sphere’s Y Location driver graph. The default 1:1 graph (i.e. Expanded Polynomial) trace is already there.
Press N to display the View Properties window.
Add Variable, and choose Single Property from drop down box.
Choose Cube as the driving object in the Prop: box.
Now I need to enter the RNA Path for the Cube’s X Location…
…THIS IS THE CRUCIAL BIT: Went to the cube’s Location X: box on the Transform panel. Right clicked and chose Copy Data Path. Went back to the driver’s RNA Path box and pasted value in. It pastes just the word location. But this is not enough. Need to specify X, Y or Z, not just location. By trial and error I found that I need to change this to location[0] to specify I want to use the X location of the cube (or 1 for y, 2 for z).
Oh, and at the top of the Drivers panel, the Type: must be set to “Averaged Value”, not “Scripted expression” or whatever it may be set to. And you have to remember to press Update Dependencies to “make it so”… phew!
Note: Seems odd that when choosing Copy Data Path, Blender doesn’t copy the exact data path (i.e. location[0] ) that is actually required by the RNA Path box of the driver.
what if the drive is on the offset property of an object’s UV mapping. It does not seem to work. The offset value does not update.
Any idea? Thank you!
